1. Field of the Invention
This invention relates to a self-adhering silicone composition, and, more particularly, to a self-adhering silicone composition that can achieve strong adhesion with superior durability.
2. Description of Prior Art
When a silicone rubber composition, which usually has release properties, is adhered on metals or adhered on materials such as glass, ceramics, plastics, synthetic or natural fibers and rubbers under usual vulcanizing conditions, it is usually practiced to previously subject the surfaces of these substrates to a treatment by a primer, and thereafter to apply the composition to these substrates, followed by vulcanizing. However, the employment of a step of the primer treatment in a molding process makes the process complicated. Also, since the primer is usually used as a solution of organic solvents, it is required to install an equipment for exhausting the organic solvents evaporating in the molding process, or there are problems of safety and sanitation, such that workers may inhale or cutaneously respire the gas of organic solvents to cause diseases of viscera. Moreover, under the molding conditions in which a strong shear force is applied as in injection molding, there is a problem that a layer of the primer is flowed out or peeled. Thus, sought after is a silicone rubber composition having a self-adhering property and requiring no primer treatment.
Conventionally known as such a self-adhering silicone rubber composition are, for example, silicone rubber compositions in which peroxysilanes such as vinyl-tris(t-butylperoxy)silane, triphenyl(t-butylperoxy)silane, trimethyl(t-butylperoxy)silane, methylvinyl-di(t-butylperoxy)silane have been added as a component for imparting adhesion properties (Japanese Unexamined Patent Publication (KOKAI) No. 24973/1985), and silicone rubber compositions in which silane coupling agents such as vinyl trimethoxysilane, vinyl triethoxysilane, .gamma.-glycidoxypropyl trimethoxysilane, .gamma.-methacryloxypropyl trimethoxysilane have been added (Japanese Examined Patent Publication (KOKOKU) No. 39817/1981).
These self-adhering silicone rubber compositions in which the peroxysilanes have been added, however, have insufficiency in adhesion properties. Those in which the silane coupling agents have been added have also the problem that they have insufficiency in adhesion properties and adhesion durability.